Foamy / oily looking patches on pool water

[mts37]

Converted to SWG this year on opening.
Used bleach for initial chlorine to get to SLAM level and then also had SWG (IC40) at 100% for the last few days.

Water clearing up now - no longer dark green just teal/cloudy and getting better day by day. Not unusual for me for the sand filter to clear up this slowly on opening.
However the surface of the water is COVERED in foamy blotches almost looks like an oil slick.

only thing I have added to the pool since startup:
1. Liquid chlorine for initial SLAM
2. 520 lbs Morton pool salt
3. Clorox brand stabilizer
4. Sodium carbonate for pH adjustme
5. Baking soda for TA adjustment

I’ve never seen this before on my pool. Only thing different from prior years is the salt and the CYA granules (usually I’d get my CYA by using trichlor on startup).

I did use an old sock to put the CYA granules in and hung it in front of the return jet. Could there have been residual detergent/fabric softener and that’s what caused these bubbles?

more importantly - how do I get rid of it??

Latest test results
CC 0.5 (maybe not even - could barely see any pink color prior to the first drop)
FC - 15 (went up from 6 with SWG running 100% for 1.5 days)
TA - 100
PH 7.5
CYA - 40-50
CH - 75


thanks,
Matt

 

[YippeeSkippy]

First question- You converted from what to the SWG? How did you normally sanitize your pool before?

Did you add Clorox or other liquid bleach that contains polymers? That stuff isn't meant for pools anymore since they added polymers. Darn it.

No cheap algaecides or clarifiers added, right??


Sidenote: Did you test your salt level before adding salt??

Maddie

 

[mts37]

@YippeeSkippy
Answers to your questions:
1. Converted from using bleach
2. Never added Clorox or other polymer containing bleaches
3. Never added an algaecide or clarifier
4. I did not - I thought I had purchased the salt testing kit but I did not. However based on the amount of bleach added last year I should have had maximum a few 100ppm salt. Then over the winter we had a lot of rain and I had to drain probably a foot of water. Salt *should be* pretty close to target now.

 

[YippeeSkippy]

Hmmmmmm.... well darn. None of the obvious reasons for foam.

I think the best thing to try is to take your FC up to 20ppm (50ppm CYA = 20ppm SLAM process level) as chlorine is just about always the cure for problems like this. See if a couple of days at SLAM level and keeping the pump running helps clear this up?

You have sand in the filter and not some *alternative* filter media, right?

Maddie

 

[Donldson]

What specific liquid chlorine did you use upon opening? Just want to make sure we're covering all of our bases, checking under every rock.

Did you close and open the pool yourself or did you bring someone in to do it?

 

[mts37]

What specific liquid chlorine did you use upon opening? Just want to make sure we're covering all of our bases, checking under every rock.

Did you close and open the pool yourself or did you bring someone in to do it?

“Pool Essentials chlorinating liquid” from Walmart. Towards end of season they usually run out of that and I buy “great value concentrated bleach” (not any of the splash less, etc. varieties).

last year Walmart was out of everything and I bought some garbage brand from Lowe’s (but again - not any of the splash free etc.). I did not notice any foaming during closing.

I have always closed and opened the pool myself.

 

[mknauss]

I have always closed and opened the pool myself.

Do you use anitfreeze?

 

[mts37]

Do you use anitfreeze?

Yes, antifreeze in the pump suction line that I can’t blow out completely - usually just half a gallon or so. Do it every year and then on opening I go straight to waste with the initial pump flow. I know this gets a good amount of it out because the filter sight glass turns pink.

 

[mts37]

I should also add that I think this started happening only after adding the cya granules via the old sock.

Although I think I remember the edges of the water getting foamy after adding the salt.

One other thing - I had to change my pump seal this year and I followed the instructions from Hayward which said to “lubricate and clean the impeller hub and seal recess with a dilute solution of liquid soap”. I used maybe a drop of Dawn when doing this. I had the pump going for awhile before the surface was covered in this foam though so I feel like that’s unrelated.

 

[mts37]

UPDATE:
So the foam is definitely linked to the SWG turning on. Yesterday after initially posting, I turned the SWG down to 20% from 100%. I checked the pool this morning and all the foam was gone.
I turned the SWG back to 100%, then checked in about an hour - the foam was back looking exactly like the original pics. I then turned it to 0% and checked an hour later - foam gone!

so what is happening? I know I read before about out gassing co2 with SWG running - is this it?? Seems odd it would make distinct foam “pockets” on the surface that don’t want to merge with eachother.

 

[mknauss]

Under certain chemistry and water temperature conditions, we have had reports of 'foam', or very tiny bubbles, associated with the SWCG. It does not effect water chemistry. It typically clears up once the water temperature rises, etc.